If you are not increasing the number of data, integer or real variables or creating new variables, there is no need to set up a variables file. Quantum will read the default values from its own variables file, as follows:

This gives you the 1000 data variables, 100 real variables and 200 integer variables mentioned in Basic elements.

The second statement (colreal cx c) informs Quantum that variables referred to as cx are, in fact, data variables whose contents are to be treated as real numbers.